What I did is build a OS install (2000, XP or 2003), then go to windows update with the PC, once it gives me a list of available updates, I can click on the 'Details' link in the updates description, then there should be a link to download the file in the pop up window that comes up, its like 2 or 3 clicks in to get to the actual file.
Download the file to a folder on your file server, or local PC.
QChain.exe has to be in the folder with the downloaded updates and you need to create a CMD file like the following :>
"\\Server\Share\WindowsXP-KB913580-x86-ENU.exe" -Z -Q -M
"\\Server\Share\Qchain.exe"
Just add more lines like line1 for all the updates (change the name of course to match the downloaded filename), the file is named, UpdateXP.CMD.
Then next time I can just open the updatexp folder and 2click UpdateXP.CMD and all the updates will be ran, with only 1 click.